1. Field of the Invention
The present invention relates to golf club heads, more particularly of the composite metal “wood” type, and a method of making golf club heads.
2. Description of the Background and Relevant Information
Wood-type golf club heads traditionally were made from wood, e.g., persimmon. However, with advances in materials, wood-type golf club heads are currently predominantly made from high performance metals such as titanium, and other materials such as fiber-reinforced plastics. Many club heads made from fiber resin composite materials are compression molded around relatively rigid molding cores. In instances where a hollow interior cavity is desired, dispersible cores made from meltable materials such as wax or low melting point metals have been employed.
Wood-type club heads made predominantly of metal may be fabricated by welding or adhesively joining together edges of two or more thin sections of a club head shell made of metal such as stainless steel, beryllium copper, aluminum, titanium, etc., thereby producing a one-piece shell.
For some years now, heads made entirely of a composite material, with the exception of the sole, have been manufactured. Such types of constructions are rarely favored by professional players because they are most often made of a single element, by the compression molding method, without any particular regard to the distribution of mass.
A head made of a plastic material is disclosed in British Patent Publication No. 2,128,539. This head is made of a single thermoplastic element injected into a mold around a meltable core. The head thus manufactured does not allow a good control over the trajectory of the balls because the problem of balancing the club is not resolved.
U.S. Pat. No. 5,000,454 discloses a head made of a reinforced plastic material and comprising an element acting both as the reinforcement of the striking face and as the balancing weight. However, such a structure does not yet permit the club to be balanced satisfactorily.
U.S. Pat. No. 6,824,636 B2 is directed to a method for the manufacture of a hollow three-dimensional fiber golf club head wherein a fluid-removable core shaped in the general form of the golf club head is placed in a flexible pressurizable bladder surrounding the core. At least one ply fiber impregnated with a curable resin is wrapped over the core and bladder, and a cured part is formed by pressurizing the bladder while the core, bladder and impregnated fiber is in a female mold to force the plies against the inner surface of the mold. After heating to cure the resin, the bladder and the fluid removable core is removed from the interior of the cured part by disintegrating the core with a fluid sufficient to allow removal of the bladder. This method is complex and difficult of reproduction on a commercial scale.